1. Field of the Invention
The present invention relates to a method of fabricating a capacitive touch-screen panel, and more particularly, to a method of fabricating a capacitive touch-screen panel that can efficiently reduce the fabrication cost of a touch screen and greatly simplify the fabrication process of the touch-screen panel.
2. Discussion of Related Art
In general, a touch screen is an input apparatus that allows all types of people to dialogically and intuitively manipulate a computer using only contacts of a finger with buttons indicated on a display unit.
Touch screens are divided into resistive touch screens, capacitive touch screens, infrared touch screens, and ultrasonic touch screens. Currently, resistive touch screens are being widely used, while capacitive touch screens are being used to minimize thicknesses.
Specifically, a capacitive touch screen includes a conductive light transmission plate formed of indium tin oxide (ITO), an electrode unit formed of powdered silver paint on an edge of the conductive light transmission plate, and an insulating coating unit configured to insulate a lower portion of the electrode unit from other elements.
Meanwhile, the conductive light transmission plate includes an ITO film formed of a light-transmissive resin and an ITO coating layer formed by coating a conductive material under the ITO film.
In the case of the above-described conventional capacitive touch screen, when a finger contacts a top surface of the conductive light transmission plate, each of electrodes disposed on four sides of the top surface of the conductive light transmission plate can detect a touched position with a variation in capacitance due to the contact with the finger.
However, the following problems may be caused during the fabrication of a conventional capacitive touch-screen panel.
First, after patterning individual touch screens, it is difficult to maintain a precise margin during an interlayer lamination process. That is, signal interference and an aperture ratio may be increased due to shift or overlapping.
Second, it is difficult to maintain a precise alignment margin between a conventional light transmission plate formed of ITO and an outer electrode unit. That is, it may be difficult to precisely control a screen printing process using an Ag paste through an outer reference hole and also hard to check the light transmissions plate with the naked eye.
Third, after performing a screen printing process, when an Ag paste is cured at a high temperature, cracks may occur in a fine ITO line.
Fourth, many defects such as air bubbles, alien substances and scratches, may occur during a sheet-state interlayer lamination process.
Fifth, since a sheet-state film is thin, it may be difficult to treat the sheet-state film and prevent the sheet-state film from being wrinkled before a lamination process.